Traditional cursor control devices for controlling movement of a cursor on a display of an electronic device include arrow keys, function keys, mice, track balls, joysticks, j-keys, touchpads, touch screens, light pens, tablets and other similar devices for controlling cursor movement and selecting items or functions on the display. Although these traditional cursor control devices are generally satisfactory for many applications, in environments in which the cursor control device must operate in a limited workspace and fit within the form factor of an electronic device, such as a laptop computer, personal digital assistant (PDA), wireline or wireless telephone, video game or other similar electronic device, traditional cursor control devices do not provide sufficient cursor control speed or accuracy.
In addition, many compact electronic devices suffer from small dynamic range, limited by either available space or human precision. For example, the capacitive workspace on a touchpad positioning controller of a laptop computer usually is not able to be accurately mapped to the entire laptop display with sufficient pixel-level resolution. As a result, either multiple swipes are necessary to navigate the full screen, or cursor acceleration algorithms are required that are often difficult to control.
Recently, puck-type pointing devices have been introduced to the laptop and hand held device industries to overcome many of the limitations of earlier cursor control devices. Puck-type pointing devices are compact puck-shaped devices that may be manipulated by a user's finger to move within a puck field of motion. The position of the puck in the puck field of motion is sensed using a variety of electrical, electromagnetic and optical techniques, and the position of the puck is mapped to a cursor position on a display. Examples of puck-type pointing devices are described in U.S. Pat. No. 6,084,570 to Milroy, entitled “Compact Cursor Controller Structure For Use With Laptop, Notebook and Hand-Held Computers and Keyboards,” U.S. Pat. No. 5,771,037 to Jackson, entitled “Computer Display Cursor Controller,” U.S. Pat. No. 6,278,440 to Katsurahira et al., entitled “Coordinate Input Apparatus and Position-Pointing Device,” and U.S. patent application Ser. No. 10/723,957 of Harley et al., entitled “Compact Pointing Device.”
However, puck-type pointing devices also suffer from small dynamic range when used in conjunction with large displays, such as those found on laptop computers and PDAs. There is therefore a need for a positioning controller on an electronic device that provides improved dynamic range with sufficient cursor control speed and accuracy.